Maximum Torque Per Ampere Control of a Direct Torque-Controlled PMSM in a Stator Flux Linkage Synchronous Frame

This paper proposes a novel method of using maximum torque per ampere (MTPA) control for direct torque control (DTC) of a permanent-magnet synchronous motor (PMSM) in the stator flux linkage synchronous (M-T) frame. The stator flux vector estimation of DTC enables use of the M-T frame. Consideration of the magnetic saturation and cross-coupling effects in PMSMs requires significant complexity in most of the mathematical models using the rotor synchronous (d-q) frame. In the M-T frame, the mathematical model for MTPA control requires only three parameters that can be determined from only three measured points. The validity of the proposed method is confirmed by experimental results.